A ratio of the dollarvalue of a company's new orders booked to the amount it has shipped and billed. A ratio of 1 means that the company can fill and ship orders as quickly as they arrive. A ratio greater than 1 means that it has more orders than it can readily fill and a ratio less than 1 means that it has excess capacity to fill orders. The book to bill ratio is also tracked on an industry-basis and is widely used as an indication of the state of the semiconductor industry.